A strong 6.4-magnitude earthquake struck off the Pacific nation of Tonga today, US seismologists said, but there were no immediate reports of damage and no tsunami warning was issued.

A strong 6.4-magnitude earthquake struck off the Pacific nation of Tonga on Saturday, US seismologists said, but there were no immediate reports of damage and no tsunami warning was issued.

The quake happened at 11:08pm (1008 GMT) 78 kilometres (49 miles) from the town of Neiafu, on the south coast of the island Vava'u, at a depth of about 130 kilometres (80 miles), the US Geological Survey (USGS) said.